JayM2,
When the noise occurs, where does it come from ?
On mine it seems to be from the area to the left of the speedometer, which is nowhere near the windscreen top.
Somebody else in an earlier thread had the noise, and the Dealer fixed it by (and I quote) "The packing in the Windscreen pillars was loose, and they re-packed them".
He also said this was done without the need to remove the Windscreen.
When you say " had the problem for several months" is your
MCS the same as mine i.e. the new build with the turbocharger ?